DESCRIPTION

The Y, U, V pixel streams are converted into an ABGR pixel stream. All pixel components are 8-bit unsigned integers. The Y buffer has dimensions w and h. The U and V buffers have dimensions w/4 and h.
Dimension w is assumed to be a multiple of 4. In each row, every 4 Y values use the same U and V values.

The alpha values for this function work in the following fashion:

o
If A_array pointer is not NULL, the values are taken from there. It has to have the same dimensions as the Y buffer.

o
If A_array pointer is NULL, the alpha values for every pixel are set to A_const.